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51.
On vicinal Si(001) surfaces, dependence of growth morphology on the applied strain direction and formation of vacancy lines from Ag-induced missing dimer vacancies are studied. Both phenomena are intimately related to the anisotropic nature of the strain field which originates from the surface dimerization. Strain relief mechanism, reflecting on the surface morphology, is shown to be different in two orthogonal directions. Normal to the steps, step-pair bunching and waving lead to formation of hillocks and pits. Along the step direction, bending of step pairs forms a cusp which later develops into a deep groove. Toward the atomic scale, the formation of the vacancy lines is driven by the short-range attractive interaction between the vacancies in adjacent dimer rows and the long-range repulsive interaction between them in the same dimer row. A full form and magnitudes of the interactions are derived from the thermally-excited wandering of the vacancy lines formed by a nominal amount of Ag depositing onto the surface. 相似文献
52.
Electroosmosis experiments through a cation-exchange membrane have been performed using NaCl solutions in different experimental situations. The influence of an alternating (ac) sinusoidal perturbation, of known angular frequency and small amplitude, superimposed to the usual applied continuous (dc) signal on the electroosmotic flow has been studied. The experimental results show that the presence of the ac perturbation affects the electroosmotic flow value, depending on the frequency of the ac signal and on the solution stirring conditions. In the frequency range studied, two regions have been observed where the electroosmotic flow reaches a maximum value: one at low frequencies (Hz); and another at frequencies of the order of kHz. These regions could be related to membrane relaxation phenomena. 相似文献
53.
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55.
Summary. Two main types of binary systems with distinctive solubility behavior under sub- and supercritical conditions were used to
subdivide ternary water-salt systems into three classes. Characteristic features of solubility behavior and phase equilibria
in ternary water-salt systems of each class at temperatures above 200°C are discussed on the basis of available experimental
data and some conclusions obtained as a result of theoretical derivation of fluid and complete phase diagrams.
Corresponding author. E-mail: Valyashko@IGIC.RAS.RU
Received September 25, 2002; accepted (revised) November 28, 2002
Published online April 24, 2003
RID="a"
ID="a" Dedicated to Prof. Dr. H. Gamsjaeger on the occasion of his 70th birthday anniversary 相似文献
56.
C. Aslangul M. Barthélémy N. Pottier D. Saint-James 《Journal of statistical physics》1991,65(3-4):695-713
The random walk of a particle on a directed Bethe lattice of constant coordinanceZ is examined in the case of random hopping rates. As a result, the higher the coordinance, the narrower the regions of anomalous drift and diffusion. The annealed and quenched mean square dispersions are calculated in all dynamical phases. In opposition to the one-dimensional (Z=2) case, the annealed and quenched mean quadratic dispersions are shown to be identical in all phases.We shall employ indifferently the expressions Bethe lattice or infinite Cayley tree to denote an infinite ramified lattice of constant coordinanceZ.(4, 5) 相似文献
57.
The conformal charge is an important quantity which characterizes the nature of the two-dimensional phase transition. We report a first attempt to use a new numerical method to calculate the conformal charge. In this paper, we apply our method to the 2-dimensional,
4, continuous-spin Ising model. By varying the parameters in the Hamiltonian, one can change continuously from the known Gaussian limit to the Ising limit. It is well known that the critical points for these two systems are not in the same universality class. We study this behavior for the Gaussian model, the single-well 4 model, the border model, and the double-well
4 model for a large lattice. Our results, while giving a good general picture, are not so far sufficient to differentiate whether the non-Gaussian cases studied belong to the Ising model universality class or not. Further studies of other lattice sizes should serve to improve greatly our conclusions. 相似文献
58.
W Schoner 《Angewandte Chemie (International ed. in English)》1971,10(12):882-889
The transport of Na+ out of the cell and K+ into the cell against a concentration gradient is catalyzed by a (Na+ + K+)-activated ATPase. The way in which the cations pass through the cell membrane has not yet been elucidated. Studies on the ATP hydrolysis revealed a Na+-dependent phosphorylation of the enzyme protein; the conformation of the enzyme also appears to change. The energy required for transport of the cations against their concentration gradients is probably provided by K+-dependent hydrolysis of the enzyme-bound phosphate. The enzyme can synthesize ATP from inorganic phosphate and ADP on reversal of the cation concentration gradient. By keeping the enzyme in a particular conformation, the cardiac glycoside ouabain specifically inhibits the Na+ pump. 相似文献
59.
Emerson Lourenço 《Polymer Degradation and Stability》2006,91(12):2968-2978
The influence of photochemical aging of in situ polymerized PS/AES blends on their mechanical properties has been studied. The PS/AES blends were subjected to photochemical aging for 168 h and 720 h. Tensile properties and Izod impact resistance of aged and non-aged samples were evaluated. The mechanical properties of the PS/AES blends are influenced by the polymerization temperature and blend composition and represent a balance between the toughness of EPDM and the stiffness of SAN in the PS matrix. Even though the impact resistance and strain at break of HIPS are higher than those of the PS/AES blends, after the aging period all PS/AES blends showed higher strain at break than HIPS. PS/AES blends present higher photochemical stability than HIPS. 相似文献
60.
There is no universal method to perform dynamic analysis on solid rubber anti-vibration systems. In this article, an equivalent damping ratio is introduced to account for rubber hysteresis using a resilience experiment. A new concept, NFR (Natural Frequency Region), is defined for dynamic evaluation based on natural characteristics of a rubber anti-vibration system itself. Two typical industrial products were selected to verify the proposed NFR approach. The verification procedure involves three parts: natural frequencies, harmonic spectra and impact responses. The dynamic responses from both simulation and experiment have been compared and have not only demonstrated that the proposed approach is reliable but that it could also be used to guide the design of rubber anti-vibration systems in industry. The key points for applying this approach are also presented through the verification procedure. 相似文献